A door locking system for a vehicle, in which a latch is rotationally driven by a latch driving motor to bring the door in a fully closed state when a door is brought in a half closed state, is known as one of the above-described door locking systems for the vehicle. Here, when the door is brought in the fully closed state, a sound-proofing member is strongly pressed between the door and the vehicle body, and the latch and a pawl are pressed each other by the reaction force to be frictionally engaged. Then, the frictional engagement leads to an operational resistance when operating a door handle. Thus, the known door locking system for the vehicle is provided with a release motor in addition to the latch driving motor, and the release motor rotationally drives the pawl depending on the operation of the handle to disengage the pawl from the latch (for example, refer to JP 2001-98819A, paragraph [0025], [0028], FIG. 2).
However, the manufacturing cost for the aforementioned known door locking system for the vehicle increases because the door locking device is provided with two power sources, one is for the latch driving motor and the other is for the release motor, and thus prohibiting the progress of this kind of door locking system for the vehicle.
A need exists for a seat for a vehicle which is not susceptible to the drawback mentioned above.